#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>

int ticket = 1000;

pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;   // 定义一把全局的锁

void* routine(void* args)
{
    const char* id = static_cast<const char*>(args);
    while(true)
    {
        pthread_mutex_lock(&lock);  // 加锁
        if (ticket > 0)
        {
            usleep(1000);
            printf("%s sells ticket:: %d\n", id, ticket);
            ticket--;
            pthread_mutex_unlock(&lock);    // 解锁
        }
        else
        {
            pthread_mutex_unlock(&lock);    // 解锁
            break;
        }
    }

    return nullptr;
}

int main()
{
    pthread_t t1, t2, t3, t4;
    pthread_create(&t1, nullptr, routine, (void*)"thread 1");
    pthread_create(&t2, nullptr, routine, (void*)"thread 2");
    pthread_create(&t3, nullptr, routine, (void*)"thread 3");
    pthread_create(&t4, nullptr, routine, (void*)"thread 4");

    pthread_join(t1, nullptr);
    pthread_join(t2, nullptr);
    pthread_join(t3, nullptr);
    pthread_join(t4, nullptr);

    return 0;
}